Recently a very nice little French language book was published by Editions De Krijger, in Belgium:
'Beuteflugzeuge' Les appareils étrangers au sein de la Luftwaffe (1938-1945), by Jean-Louis Roba.
I found only one location on the net presenting the book (including the cover):
http://www.ritteredizioni.com/index....chk=1&Itemid=1
The book - which was kindly sent to me by the author as a courtesy copy, contains 96 pages in A5 format - each page featuring an average two photos of non-German airplanes in Luftwaffe service, or captured by German troops.
Although we've already seen quite a few of the photos in various publications, many of them are unknown to me.
A short introduction gives an overview of the airplanes found in every country overrun by the German Army, or allied to the IIIrd Reich.
Recommended.